1,6-Substituted 3,8-Dihalogenopyrene And Process For Producing The Same

ABSTRACT

A 3,8-dihalogeno-1,6-substituted pyrene represented by a following general formula (2):  
                 
 
wherein R 1  and R 2  each independently represents a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, unsubstituted aryloxy group having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a silyl group; and X represents a halogen atom. It is useful as an intermediate for dyes or so, as intermediates for a charge transporting material of particularly an electronic photographic photosensitive article, for a material for an organic electroluminescence device and for a hole transporting material or a light emitting material for an organic electroluminescence device.

TECHNICAL FIELD

The present invention relates to a 3,8-dihalogeno-1,6-substituted pyrene and a process for producing the 3,8-dihalogeno-1,6-substituted pyrene.

BACKGROUND ART

Making a halogeno group as a reaction point, various pyrene compounds substituted at 4 positions are deliverable from the 3,8-dihalogeno-1,6-substituted pyrene. It is a compound having utility as an intermediate for dyes or so, and especially as an intermediate for a charge transporting material of electronic photographic photosensitive article, for a material of organic electroluminescence (“electroluminescence” will be occasionally referred to as “EL”, hereinafter) device, for a hole transporting material or a light emitting material of an organic electroluminescence device.

Regarding with the 3,8-dibromo-1,6-substituted pyrenes, Journal of Materials Chemistry, 2000,10, pp 315-319 discloses a compound whose substituent is 3,5-di-t-butylbenzene. Further, Math. -fys. Medd (1941), Volume 18, Number 22, discloses a compound having a following structure:

It is generally known that a mixture of 1,6-substituted dibromopyrene and 1,8-substituted dibromopyrene is obtained by di-brominating pyrene [Journal of Chemical Society Perkin, Number 1, page 1622 (1972), etc.)]. However, considering about an effect of re-crystallization, despite the easiness in getting high purity product of the (1,6-) article owing to its high crystallinity, it is impossible to easily improve purity of the (1,8-) article because of its low crystallinity.

An object of the present invention is to provide a novel 3,8-dihalogeno-1,6-substituted pyrene having utility as an intermediate for dyes or so, and to provide an efficient process for producing the same.

DISCLOSURE OF THE INVENTION

As a result of intensive researches and studies to achieve the above object by the present inventors, it was found that an employment of 1,6-substituted pyrene as a starting material and a halogenating its 3,8-position enable to efficiently produce 3,8-dihalogeno-1,6-substituted pyrene resultantly completing the present invention.

Namely, the present invention provides

-   1. A 3,8-dihalogeno-1,6-substituted pyrene represented by a     following general formula (2):     wherein R₁ and R₂ each independently represents a substituted or     unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted     or unsubstituted aryl group having 5 to 50 carbon atoms, a     substituted or unsubstituted aralkyl group having 7 to 50 carbon     atoms, a substituted or unsubstituted cycloalkyl group having 3 to     50 carbon atoms, a substituted or unsubstituted alkoxyl group having     1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group     having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a     silyl group; and X represents a halogen atom; -   2. The 3,8-dihalogeno-1,6-substituted pyrene according to the above     term 1, wherein R₁ and R₂ each independently represents at least one     selected from a group consisting of a substituted or unsubstituted     alkyl group having 1 to 50 carbon atoms, a substituted or     unsubstituted aryl group having 5 to 50 carbon atoms, a substituted     or unsubstituted aralkyl group having 7 to 50 carbon atoms, and a     substituted or unsubstituted cycloalkyl group having 3 to 50 carbon     atoms. -   3. The 3,8-dihalogeno- 1,6-substituted pyrene according to the above     term 1, wherein X is a bromine atom. -   4. A process for producing a 3,8-dihalogeno-1,6-substituted pyrene     which comprises steps of: -   halogenating a 1,6-substituted pyrene represented by a following     general formula (1):     wherein R₁ and R₂ each independently represents a substituted or     unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted     or unsubstituted aryl group having 5 to 50 carbon atoms, a     substituted or unsubstituted aralkyl group having 7 to 50 carbon     atoms, a substituted or unsubstituted cycloalkyl group having 3 to     50 carbon atoms, a substituted or unsubstituted alkoxyl group having     1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group     having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a     silyl group; and -   forming the 3,8-dihalogeno-1,6-substituted pyrene represented by a     following general formula (2):     wherein R₁ and R₂ each independently represents the same as the     above description; and X represents a halogen atom; -   5. The process for producing a 3,8-dihalogeno-1,6-substituted pyrene     according to the is above term 4, wherein R₁ and R₂ each     independently represents at least one selected from a group     consisting of a substituted or unsubstituted alkyl group having 1 to     50 carbon atoms, a substituted or unsubstituted aryl group having 5     to 50 carbon atoms, a substituted or unsubstituted aralkyl group     having 7 to 50 carbon atoms, and a substituted or unsubstituted     cycloalkyl group having 3 to 50 carbon atoms; and -   6. The process for producing a 3,8-dihalogeno-1,6-substituted pyrene     according to the above term 4, wherein a halogenating agent is     N-bromosuccinimide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart showing ¹H-Nuclear Magnetic Resonance (NMR) spectrum of the compound obtained in Example 1;

FIG. 2 is a chart showing ¹H-NMR spectrum of the compound obtained in Example 2;

FIG. 3 is a chart showing ¹H-NMR spectrum of the compound obtained in Example 3;

FIG. 4 is a chart showing ¹H-NMR spectrum of the compound obtained in Example 4;

FIG. 5 is a chart showing ¹H-NMR spectrum of the compound obtained in Example 5; and

FIG. 6 is a chart showing ¹H-NMR spectrum of the compound obtained in Reference Example.

PREFERRED EMBODIMENTS TO CARRY OUT THE INVENTION

The present invention provides a process for producing a 3,8-dihalogeno-1,6-substituted pyrene represented by a following general formula (2) by halogenating 1,6-substituted pyrene represented by a following general formula (1):

wherein R₁ and R₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a silyl group; and X represents a halogen atom.

Examples of a halogen atom employed for halogenating, namely, the halogen atom represented by X in the general formula (2) include fluorine atom, chlorine atom, bromine atom, iodine atom and so on, bromine (Br) atom and iodine (I) atom being preferable.

Examples of the alkyl group represented by the above R₁ and R₂ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxyisobutyl group, 1,2-dihydroxyethyl group, 1,3-dihydroxy-isopropyl group, 2,3-dihydroxy-t-butyl group, 1,2,3-trihydroxypropyl group, chloromethyl group, 1-chloroethyl group, 2-chloroethyl group, 2-chloroisobutyl group, 1,2-dichloroethyl group, 1,3-dichloroisopropyl group, 2,3-dichloro-t-butyl group, 1,2,3-trichloropropyl group, bromomethyl group, 1-bromoethyl group, 2-bromoethyl group, 2-bromoisobutyl group, 1,2-dibromoethyl group, 1,3-dibromoisopropyl group, 2,3-dibromo-t-butyl group, 1,2,3-tribromopropyl group, iodomethyl group, 1-iodoethyl group, 2-iodoethyl group, 2-iodoisobutyl group, 1,2-diiodoethyl group, 1,3-diiodoisopropyl group, 2,3-diiodo-t-butyl group, 1,2,3-triiodopropyl group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, 2-aminoisobutyl group, 1,2-diaminoethyl group, 1,3-diaminoisopropyl group, 2,3-diamino-t-butyl group, 1,2,3-triaminopropyl group, cyanomethyl group, 1-cyanoethyl group, 2-cyanoethyl group, 2-cyanoisobutyl group, 1,2-dicyanoethyl group, 1,3-dicyanoisopropyl group, 2,3-dicyano-t-butyl group, 1,2,3-tricyanopropyl group, nitromethyl group, 1-nitroethyl group, 2-nitroethyl group, 2-nitroisobutyl group, 1,2-dinitroethyl group, 1,3-dinitroisopropyl group, 2,3-dinitro-t-butyl group, 1,2,3-trinitropropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, 2-norbornyl group, substituted or unsubstituted perfluoroalkyl group having 1 to 10 carbon atoms, etc.

Examples of the aryl group represented by the above R₁ and R₂ include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group, p-(2-phenylpropyl)phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylyl group and 4″-t-butyl-p-terphenyl-4-yl group, etc.

Examples of the aralkyl group represented by the above R₁ and R₂ include benzyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group, phenyl-t-butyl group, α-naphthylmethyl group, 1-α-naphthylethyl group, 2-α-naphthylethyl group, 1-α-naphthylisopropyl group, 2-α-naphthylisopropyl group, β-naphthylmethyl group, 1-β-naphthylethyl group, 2-β-naphthylethyl group, 1-β-naphthylisopropyl group, 2-β-naphthylisopropyl group, 1-pyrrolylmethyl group, 2-(1-pyrrolyl)ethyl group, p-methylbenzyl group, m-methylbenzyl group, o-methylbenzyl group, p-chlorobenzyl group, m-chlorobenzyl group, o-chlorobenzyl group, p-bromobenzyl group, m-bromobenzyl group, o-bromobenzyl group, p-iodobenzyl group, m-iodobenzyl group, o-iodobenzyl group, p-hydroxybenzyl group, m-hydroxybenzyl group, o-hydroxybenzyl group, p-aminobenzyl group, m-aminobenzyl group, o-aminobenzyl group, p-nitrobenzyl group, m-nitrobenzyl group, o-nitrobenzyl group, p-cyanobenzyl group, m-cyanobenzyl group, o-cyanobenzyl group, 1-hydroxy-2-phenylisopropyl group, 1-chloro-2-phenylisopropyl group, etc.

Examples of the cycloalkyl group represented by the above R₁ and R₂ include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.

Examples of the alkoxyl group represented by the above R₁ and R₂ include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, various pentyloxy groups, various hexyloxy groups, etc.

Examples of the aryloxy group represented by the above R₁ and R₂ include phenoxy group, tolyloxy group, naphthyloxy group, etc.

Examples of the halogen atom represented by the above R₁ and R₂ include fluorine atom, chlorine atom, bromine atom, iodine atom, etc.

Examples of the substituent for the group represented by R₁ and R₂ include an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, an aryloxy group having 5 to 18 carbon atoms, an aralkyloxy group having 7 to 18 carbon atoms, an arylamino group having 5 to 16 carbon atoms, a nitro group, a cyano group, an ester group having 1 to 6 carbon atoms, a halogen atom, etc.

Specific examples of the 3,8-dihalogeno-1,6-substituted pyrene represented by the general formula (2) of the present invention include the following compounds, though not limited thereto.

A process for producing 1,6-substituted pyrene represented by the general formula (1) is selectable from well known process without particularly specified, and may be introduced, for example, from 1,6-dibromo pyrene [Journal of Chemical Society Perkin, Vol. 1, page 1622 (1972)], etc.

Examples of a reagent employed for halogenation of 1,6-substituted pyrene represented by the general formula (1), when a halogen atom used in the halogenation is bromine, include bromine atom, N-bromosuccinimide (NBS), KBr, KBrO₃, AlBr₃, PBr₃, SbBr₃, FeBr₂, PyHBrCl₂, Bu₄NBr₃ and so on while bromine atom and NBS are preferable.

When the halogen atom used in the halogenation is except bromine atom, the above examples of whose bromine atom is replaced with the halogen atom are applicable.

Regarding with the halogenation, it is preferable to be carried out among an organic solvent or a sulfuric acid such as tetrachloromethane, chloroform, methylene chloride, acetic acid, pyridine, dimethylformamide (DMF), etc.

Moreover, a peroxide such as benzoyl peroxide (BPO), 2,2′-azobisisobutyronitrile (AIBN), m-chloroperbenzoic acid (mCPBA) or so and a heavy metal salt may be added to the halogenation reaction process, and a light irradiation may be carried out during the process.

With regard to a reaction temperature for the halogenation, it is usually within a range of from a room temperature to 150° C. and preferably within a range of from the room temperature to 100° C. With regard to a reaction time for the halogenation, it is usually within a range of from 1 to 120 hours, preferably within a range of from 6 to 18 hours.

A amination of 3,8-dihalogeno-1,6-substituted pyrene of the present invention with a use of a compound which is expressed, for example, by H—NR₃R₄ enables to prepare a diaminopyrene derivative represented by a following general formula (3), which is practical as a charge transporting material for an electron c photographic photosensitive articles, a material for an organic electroluminescence device, a hole transporting material or a light emitting material for the organic electroluminescence device, etc.

In the general formulae (2) and (3), R₁ and R₂ each independently represent the same as those aforementioned.

Further, in the general formula (1), X is the same as those aforementioned.

In the general formula (3), R₃ and R₄ each independently represents a substituted or unsubstituted aryl group having 5 to 50 carbon atoms or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, while the above aryl group is preferable.

Examples of the aryl group represented by R₃ and R₄ are the same as those about the above R₁ and R₂.

Examples of the alkyl group represented by R₃ and R₄ are the same as those about the above R₁ and R₂.

It is preferable that the general formula (3) coincides with a diaminopyrene derivative expressed by a following general formula (4).

In the general formula (4), R₁ and R₂ each independently represents the same as those aforementioned.

In the general formula (4), A₁ and A₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryloxy group having 5 to 50 carbon atoms, a substituted or unsubstituted arylamino group having 5 to 50 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 10 carbon atoms or a halogen atom.

Specific examples of those groups include the same whose numbers of carbon atoms coincide with those described about the above R₁ and R₂.

In the general formula (4), p and q each independently represents an integer of 1 to 5, and when p or q is 2 or greater, plural A₁ or plural A₂ may be the same with, or different from each other, and may bond to each other to form a saturated or unsaturated ring.

EXAMPLES

The present invention shall be explained below in further details with reference to examples.

Example 1 Synthesis of (1,6-diisopropyl-3,8-dibromopyrene)

Under an atmospheric argon gas flow, 1,6-dibromopyrene in an amount of 20 g (55.6 millimole), isopropylmagnesiumbromide in an amount of 117 milliliter [117 millimole, 1 mole/litter (THF: tetrahydrofuran)], (diphenylphosphinoferrocene)palladium(II)dichloride in an amount of 2.27 g (5% by mole) and dried dioxane in an amount of 130 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 500 milliliter, and the resultant solution was stirred with heating at a temperature of 90° C. for 8 hours.

After the completion of the reaction, adding 100 milliliter of dilute hydrochloric acid, an organic layer was separated and concentrated under a reduced pressure. Then, the organic layer was passed through a silicagel short column, and after concentrating under the reduced pressure again, a precipitated crystal was separated by filtration and as a result, 7.4 g of 1,6-diisopropyl pyrene (pale yellow powder) was obtained (the yield: 31%).

Subsequently, under an atmospheric argon gas flow, 1,6-diisopropylpyrene in an amount of 7.4 g (25.9 millimole), N-bromosuccinimide in an amount of 11 g (62.1 millimole) and dried dimethylformamide (DMF) in an amount of 250 milliliter were placed into an eggplant flask equipped with a cooling pipe and having a capacity of 1 liter, and the resultant solution was stirred with heating at a temperature of 50° C. for 4 hours.

After the completion of the reaction, adding 250 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of methanol, and as a result, 3.2 g of pale yellow powder was obtained (the yield: 28%)

The pale yellow powder was identified as 1,6-diisopropyl-3,8-dibromopyrene from the result of ¹H-NMR spectrum (refer to FIG. 1) and Field Desorption Mass Spectrum (FD-MS) measurement.

Example 2 Synthesis of (1,6-dicyclohexyl-3,8-dibromopyrene)

Under an atmospheric argon gas flow, 1,6-dibromopyrene in an amount of 20 g (55.6 millimole), cyclohexylmagnesiumbromide in an amount of 117 milliliter (117 millimole, 1 mole/litter (THF)), (diphenylphosphinoferrocene)palladium(II)dichloride in an amount of 2.27 g (5% by mole) and dried dioxane in an amount of 80 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 500 milliliter, and the resultant solution was stirred with heating at a temperature of 90° C. for 8 hours.

After the completion of the reaction, adding 100 milliliter of dilute hydrochloric acid, an organic layer was separated and concentrated under a reduced pressure. Then, the organic layer was passed through a silicagel short column, and after concentrating under the reduced pressure again, a precipitated crystal was separated by filtration and as a result, 7.0 g of 1,6-dicyclohexylpyrene (pale yellow powder) was obtained (the yield: 71%).

Subsequently, under an atmospheric argon gas flow, 1,6-dicyclohexylpyrene in an amount of 10.4 g (28.4 millimole), N-bromosuccinimide in an amount of 12.1 g (68.2 millimole) and dried dimethylformamide (DMF) in an amount of 300 milliliter were placed into an eggplant flask equipped with a cooling pipe and having a capacity of 1 liter, and the resultant solution was stirred with heating at a temperature of 50° C. for 7 hours.

After the completion of the reaction, adding 300 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of methanol and as a result, 6.2 g of pale yellow powder was obtained (the yield: 42%).

The pale yellow powder was identified as 1,6-dicyclohexyl-3,8-dibromopyrene from the result of 1H-NMR spectrum (refer to FIG. 2) and FD-MS measurement.

Example 3 Synthesis of 1,6-di(2-naphthyl)-3,8-dibromopyrene]

Under an atmospheric argon gas flow, 1,6-dibromopyrene in an amount of 10.3 g (28.6 millimole), 2-naphthylboronic acid in an amount of 11.8 g (68.7 millimole), tetrakis(triphenylphosphine)palladium(0) in an amount of 0.66 g (2% by mole), sodium carbonate aqueous solution in an amount of 43 milliliter (59.4 millimole, 2M), dimethoxyethane (DME) in an amount of 100 milliliter and dried THF in an amount of 70 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 200 milliliter, and the resultant solution was stirred with heating at a temperature of 90° C. for 8 hours.

After the completion of the reaction, adding 50 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of ethanol, and as a result. 13.2 g of pale yellow powder was obtained (the yield: 99%).

Subsequently, under an atmospheric argon gas flow, 1,6-di(2-naphthyl)pyrene in an amount of 13 g (28.6 millimole), N-bromosuccinimide in an amount of 11.8 g (68.7 millimole) and dried dimethylformamide (DMF) in an amount of 450 milliliter were placed into an eggplant flask equipped with a cooling pipe and having a capacity of 1 liter, and the resultant solution was stirred with heating at a temperature of 50° C. for 8 hours.

After the completion of the reaction, adding 300 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of methanol, and as a result, 7.0 g of pale yellow powder was obtained (the yield: 40%).

The pale yellow powder was identified as 1,6-di(2-naphthyl)-3,8-dibromopyrene from the result of ¹H-NMR spectrum (refer to FIG. 3) and FD-MS measurement.

Example 4 Synthesis of [1,6-di(2-biphenyl)-3,8-dibromopyrene]

Under an atmospheric argon gas flow, 1,6-dibromopyrene in an amount of 9.7 g (27.0 millimole), 2-biphenylboronic acid in an amount of 12.8 g (64.8 millimole), tetrakis(triphenylphosphine)palladium(0) in an amount of 1.25 g (4% by mole), sodium carbonate aqueous solution in an amount of 61 milliliter (122 millimole, 2M) and dimethoxyethane (DME) in an amount of 120 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 200 milliliter, and the resultant solution was stirred with heating at a temperature of 90° C. for 8 hours.

After the completion of the reaction, adding 50 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of ethanol, and as a result, 13.3 g of 1,6-di(2-biphenyl)pyrene (white powder) was obtained (the yield: 97%).

Subsequently, under an atmospheric argon gas flow, 1,6-di(2-biphenyl)pyrene in an amount of 13.2 g (26.1 millimole), N-bromosuccinimide in an amount of 9.8 g (55 millimole) and dried dimethylformamide (DMF) in an amount of 550 milliliter were placed into an eggplant flask equipped with a cooling pipe and having a capacity of 1 liter, and the resultant solution was stirred with heating at a temperature of 50° C. for 8 hours. After the completion of the reaction, adding 300 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of methanol, and as a result, 10.5 g of pale yellow powder was obtained (the yield: 61%).

The pale yellow powder was identified as 1,6-di(2-biphenyl)-3,8-dibromopyrene from the result of ¹H-NMR spectrum (refer to FIG. 4) and FD-MS measurement.

Example 5 Synthesis of 1,6-di(4-cyanophenyl)-3,8-dibromopyrene]

Under an atmospheric argon gas flow, 1,6-dibromopyrene in an amount of 7.1 g (19.8 millimole), 4-cyanophenylboronic acid in an amount of 7.0 g (47.5 millimole), tetrakis(triphenylphosphine)palladium(0) in an amount of 0.46 g (2% by mole), sodium carbonate aqueous solution in an amount of 30 milliliter (59.4 millimole, 2M), dimethoxyethane (DME) in an amount of 60 milliliter and dried THF in an amount of 70 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 200 milliliter, and the resultant solution was stirred with heating at a temperature of 90° C. for 8 hours.

After the completion of the reaction, adding 50 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of ethanol, and as a result, 7.8 g of pale yellow powder was obtained (the yield: 98%).

Subsequently, under an atmospheric argon gas flow, 1,6-di(4-cyanophenyl)pyrene in an amount of 12.8 g (317 millimole), N-bromosuccinimide in an amount of 13.5 g (76 millimole) and dried dimethylformamide (DMF) in an amount of 450 milliliter were placed into an eggplant flask equipped with a cooling pipe and having a capacity of 1 liter, and the resultant solution was stirred with heating at a temperature of 50° C. for 8 hours.

After the completion of the reaction, adding 300 milliliter of water, precipitated crystal was separated by filtration and washed with the use of 50 milliliter of water and 100 milliliter of methanol, and as a result, 16.3 g of pale yellow powder was obtained (the yield: 41%).

The pale yellow powder was identified as 1,6-di(4-cyanophenyl-3,8-dibromo pyrene from the result of ¹H-NMR spectrum (refer to FIG. 5) and FD-MS measurement.

REFERENCE EXAMPLE

(1) Preparation of Diaminopyrene Derivatives

Under an atmospheric argon gas flow, 1,6-diisopropyl-3,8-dibromopyrene in an amount of 3.0 g (6.7 millimole), m,m′-ditolylamine in an amount of 3.2 g (16.2 millimole), palladium acetate in an amount of 0.02 g (1.5% by mole), tri-t-butylphosphine in an amount of 0.04 g (3% by mole), sodium-t-butoxide in an amount of 1.6 g (16.6 millimole) and dried toluene in an amount of 75 milliliter were placed into a three-neck flask equipped with a cooling pipe and having a capacity of 300 milliliter, and the resultant solution was stirred with heating at a temperature of 110° C. for 8 hours.

After the completion of the reaction, the resultant solution was passed through a silicagel short column, and after concentrating under a reduced pressure, a precipitated crystal was separated by filtration. The crystal was washed with the use of 50 milliliter of toluene and 100 milliliter of methanol, and as a result, 4.5 g of pale yellow powder was obtained.

The pale yellow powder was identified as a following Compound (5) from the result of ¹H-NMR spectrum (refer to FIG. 6) and FD-MS measurement (the yield: 98%).

It was recognized that the peak absorption wavelength of the Compound (5) was 429 nanometers and the peak fluorescent wave length was 463 nanometers (toluene solution).

(2) Fabrication of an Organic EL Device

A 130 nanometers-thick transparent electrode made of indium tin oxide was formed on a glass substrate having a size of 25 mm×75 mm×1.1 mm.

The glass substrate was cleaned by application of ultrasonic wave in isopropyl alcohol and then by exposure to ultraviolet ray and ozone.

Subsequently, the glass substrate having the transparent electrode which had been cleaned was attached to a substrate holder of a vacuum vapor deposition apparatus. Then, after reducing a degree of vacuum in a vacuum chamber of the vacuum vapor deposition apparatus down to 1×10⁻³ Pa, a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injecting layer and cathode layer were successively laminated on an anode layer in accordance with following vapor deposition conditions. As a result, an organic EL device was fabricated.

Hole injecting layer: N′,N″-bis[4-(diphenylamino)phenyl]-N′,N″-diphenyl biphenyl-4,4′-diamine as material; vapor deposition condition of 2 nanometers/second; film thickness of 60 nanometers;

Hole transporting layer: N,N,N′,N′-tetrakis(4-biphenyl)-4,4′-benzidine as material; vapor deposition condition of 2 nanometers/second; film thickness of 20 nanometers

Light emitting layer: Employing 10-(4-(naphthalene-1-yl)phenyl)-9-(naphthalene-3-yl)anthracene (H-1) as a light emitting material, and employing the above Compound (5) as a doping material, a simultaneous vapor deposition of (H-1) and the above Compound (5) with a weight ratio of 40:2 was carried out at vapor deposition condition of 2 nanometers/second about (H-1), and vapor deposition condition of 0.2 nanometers/second about Compound (5); film thickness of 40 nanometers

Electron transporting layer: tris(8-hydroxyquinolino)aluminum as material; vapor deposition condition of 2 nanometers/second; film thickness of 20 nanometers

Electron injecting layer: lithium fluoride as material; vapor deposition condition of 0.1 nanometers/second; film thickness of 1 nanometer

Cathode layer: aluminum as material; vapor deposition condition of 2 nanometers/second; film thickness of 200 nanometers

(3) Evaluation of an Organic EL Device

As a result of subjecting the organic EL device obtained in the above term (2) to a test by feeding electric current, it was confirmed that a blue light (main wavelength of light emission: 469 nanometers) with a luminance of 827 cd/m² was emitted at a voltage of 7.3 V and a current density of 10 mA/cm².

Further, driving with a constant electric current starting from an initial luminance of 2,000 cd/m², a half lifetime of luminance when the initial luminance reduced to one half was 3,000 hours or longer.

INDUSTRIAL APPLICABILITY

The present invention enables an efficient production of 3,8-dihalogeno-1,6-substituted pyrene having utility as an intermediate for dyes or so, as intermediates for a charge transporting material of particularly an electronic photographic photosensitive article, for a material for an organic electroluminescence device and for a hole transporting material or a light emitting material for an organic electroluminescence device. 

1. A 3,8-dihalogeno-1,6-substituted pyrene represented by a following general formula (2):

wherein R₁ and R₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a silyl group; and X represents a halogen atom.
 2. The 3,8-dihalogeno-1,6-substituted pyrene according to claim 1, wherein said R₁ and R₂ each independently represents at least one selected from a group consisting of a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, and a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms.
 3. The 3,8-dihalogeno-1,6-substituted pyrene according to claim 1, wherein said X is a bromine atom.
 4. A process for producing a 3,8-dihalogeno-1,6-substituted pyrene which comprises steps of halogenating a 1,6-substituted pyrene represented by a following general formula (1):

wherein R₁ and R₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryloxy group having 5 to 50 carbon atoms, a halogen atom, a cyano group, or a silyl group; and forming the 3,8-dihalogeno-1,6-substituted pyrene represented by a following general formula (2):

wherein R₁ and R₂ each independently represents the same as the above description; and X represents a halogen atom.
 5. The process for producing a 3,8-dihalogeno-1,6-substituted pyrene according to claim 4, wherein said R₁ and R₂ each independently represents at least one selected from a group consisting of a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, and a substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms.
 6. The process for producing a 3,8-dihalogeno-1,6-substituted pyrene according to claim 4, wherein a halogenating agent is N-bromosuccinimide. 